Thanks. Yes unless you have hundreds of sets it appears there is very little chance of getting a 100% complete build. However, some people would argue this is a good thing as it forces you to figure out how to get the extra few % yourself :) I want to add some more functionality here to try and assist people in finding suitable replacement parts.

As for the MOCs, yes originally it had only a few but now that is accelerating. There are 34 right now with about 50 more in my backlog. As it becomes more popular, more people contact me asking to submit their MOCs. I still need to build the self-submit feature!

The idea of listing sets to buy to reach 100% is a good one. I haven't been too sure how much people actually find that section useful. The idea in my mind was "if you buy this set you are effectively getting 2 for 1".

Tech stack: Linux, PostgreSQL, Memcache, PHP with jQuery for front end stuff. Nothing very fancy but the algorithms have been designed (several times!) to be very fast.